There are a number of RV Parks in an around Houston. On the North side we have stayed at Thousand Trails Lake Conroe (in the Conroe/Willis area which is right on Lake Conroe; Park On the Lake in Willis on Hwy 830 West of I45-almost all of the sites on on the water; Woodland Lakes in The Woodlands just east of I45 on Hwy 242 has a couple of ponds and is nice; Rayford Crossing off of Rayford Road east of I45 in The Woodlands is nice has a small pond and is rated 10-10-10 by Trailer Life; Houston North KOA just south of Richie Road east of Hardy Street is alright without any ponds or lakes; South Main RV Park on South Main at South Loop 610 is a park without ponds but close to the Medical Center; Lakeview RV Park is beautiful, has a large pond for fishing and is on South Main and Hiram Clark- they have a free shuttle to the Medical Center and many stay there while undergoing medical treatment at the Medical Center. This park is gated with a locking gate and is a safe park; All Star RV Park on US 59 just south of downtown is close to the Medical Center - no ponds; Oasis RV Park at mile marker 10 on I45 south in LaMarque (10 miles from the Gulf Of Mexico) is located behind Ron Hoover RV and offers RV service on Heartland Products at your site. There is a county park behind Oasis where you can fish. There is also The Palms in Dickinson on Dickinson Ave south of Houston. No water but close to shopping. This park is nice but has a lousy reputation. We have stayed there for 2 weeks without any problems. They are under new ownership.
Hope this helps some. Feel free to PM me if you want any more info. We work for SE Publications doing RV Park site maps and are familiar with most of the parks in eastern Texas, and have stayed at many of them.